Correction, look for the class android, and for the method called filedir as in

$android = new Android();
define('BASE_DIR', $android->filedir);

Inspect all the methods in the android class.. one of them is responsible for what you are looking for.. If you don't find it, just extend the android class like so..

class YourClass extends android{
private $yourProperty = null;
public function __construct('redefinePropertyNeededByYourMethodAndMustBeInheritedByYourClass_YourClass,$yourProperty){
## below is pretty much the copy of the parents constructor
parent::__construct('redefinePropertyNeededByYourMethodAndMustBeInheritedByYourClass_YourClass);
$this->YourProperty = $whatEverIsYourNewProperty;
## define your method declare it as public if it is set as private above.
public function get_yourMethodOrFunction(){
## this is the part where you need to do your changes
}
return $this->get_changesYouMadeOutOftheParentsMethod;
}
## end of class YourClass